The present invention relates to mining equipment, and particularly to continuous mining machines.
Traditionally, excavation of hard rock in the mining and construction industries, has generally taken one of two forms, explosive excavation or rolling edge disc cutter excavation. Explosive mining entails drilling a pattern of holes of relatively small diameter into the rock being excavated, and loading those holes with explosives. The explosives are then detonated in a sequence designed to fragment the required volume of rock for subsequent removal by suitable loading and transport equipment. However, the relatively unpredictable size distribution of the rock product formed complicates downstream processing.
Mechanical fragmentation of rock eliminates the use of explosives; however, rolling edge cutters require the application of very large forces to crush and fragment the rock under excavation. Conventional underground mining operations may cause the mine roof (also called the hanging wall) and mine walls to become unstable. In order to prevent the walls from collapsing as the mining machine bores deeper into a mineral seam, hydraulic cylinders are used to support the mine walls. To support the hanging wall, the hydraulic cylinders often must exert forces of over 40 tons against the hanging wall. This force causes the hydraulic support to bore into the hanging wall, which weakens the hanging wall and increases the risk of falling rocks.